Delinquencies as a percentage of loans in repayment.

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Total loans in repayment.

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Loans in repayment current in percentage.

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Total loans in repayment, in percentage.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Percentage of financing receivable balance that is past due.

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Amount of financing receivable not past due.

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Amount of financing receivable past due.

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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Amount, before allowance and fees, of loans and leases receivable. Excludes loans and leases covered under loss sharing agreements.

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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

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Amount of deferred fees paid by borrowers and unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of loans that are being amortized into income as an adjustment to yield. Excludes amounts for loans and leases covered under loss sharing agreements.

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Allowance for Loan Losses - Loan Status of Personal Education Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	$ (441,912)	$ (341,121)	$ (251,475)	$ (184,701)
Loans held for investment (net of allowance for losses of $441,912 and $341,121, respectively)	24,667,792	22,270,919
Personal Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Private Education Loans	1,049,007	1,190,091
Deferred origination costs and unamortized premium/ (discount)	513	297
Allowance for loan losses	(65,877)	(62,201)
Loans held for investment (net of allowance for losses of $441,912 and $341,121, respectively)	983,643	1,128,187
Consumer Portfolio Segment \| Personal Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans current	$ 1,023,517	$ 1,172,776
Loans current, in percentage	97.60%	98.50%
Total TDR loans in repayment	$ 1,049,007	$ 1,190,091
Loans in repayment, in percentage	100.00%	100.00%
Private Education Loans	$ 1,049,007	$ 1,190,091
Deferred origination costs and unamortized premium/ (discount)	513	297
Total Personal Loans	1,049,520	1,190,388
Allowance for loan losses	(65,877)	(62,201)
Loans held for investment (net of allowance for losses of $441,912 and $341,121, respectively)	$ 983,643	$ 1,128,187
Delinquencies as a percentage of Private Education Loans in repayment	2.40%	1.50%
Consumer Portfolio Segment \| Personal Loans \| Loans delinquent 31-60 days
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans delinquent	$ 9,435	$ 6,722
Loans delinquent (in percentage)	0.90%	0.60%
Consumer Portfolio Segment \| Personal Loans \| Loans delinquent 61-90 days
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans delinquent	$ 7,172	$ 5,416
Loans delinquent (in percentage)	0.70%	0.50%
Consumer Portfolio Segment \| Personal Loans \| Loans delinquent greater than 90 days
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans delinquent	$ 8,883	$ 5,177
Loans delinquent (in percentage)	0.80%	0.40%